Sorbaria plant named ‘COUSORB05’

ABSTRACT

A new and distinct  Sorbaria  cultivar named ‘COUSORB05’ is disclosed, characterized by a compact plant size having early budding and easy care in the garden. Plants have an attractive young foliage color of pink and yellow-green for an extended period. The new variety is a  Sorbaria sorbifolia  for use as a commercial rootstock for grafting or budding onto.

Latin name of the genus and species: Sorbaria sorbifolia.

Variety denomination: ‘COUSORB05’.

BACKGROUND OF THE INVENTION

The new cultivar is a product of a breeding scheme conducted by the inventor Jacques Couturieux. The new variety was discovered in Vosges, France, as an individual seedling of the patented variety Sorbaria sorbifolia ‘Sem’, U.S. Plant Pat. No. 16,336. The new variety rose as a seedling resulting from the self-pollination of the parent variety. This plant with unique characteristics was selected during April of 2014.

Asexual reproduction of the new cultivar ‘COUSORB05’ was first performed via semi-softwood tip cuttings in Vosges, France, during June of 2014. Subsequent propagation has shown that the unique features of this cultivar are stable and reproduced true to type on successive generations.

SUMMARY OF THE INVENTION

The cultivar ‘COUSORB05’ has not been observed under all possible environmental conditions. The phenotype may vary somewhat with variations in environment such as temperature, day length, and light intensity, without, however, any variance in genotype. The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘COUSORB05’. These characteristics in combination distinguish ‘COUSORB05’ as a new and distinct Sorbaria cultivar:

-   -   1. Compact size.     -   2. Early budding.     -   3. Young leaf coloration of pink and yellow-green for an         extended period.     -   4. Cold-resistant.     -   5. Easy care in the garden, with no maintenance needed.

PARENT COMPARISON

Plants of the new cultivar ‘COUSORB05’ are similar to plants of the parent, in most horticultural characteristics. Plants of the new cultivar ‘COUSORB05’, however, differ in the following:

-   -   1. Plants of the new cultivar are more compact than the parent         variety.     -   2. New variety's young leaf coloration lasts longer than parent         variety.

COMMERCIAL COMPARISON

Plants of the new cultivar ‘COUSORB05’ can also be compared to the unnamed, unpatented Sorbaria sorbifolia sold in the nursery trade. Plants are similar in most horticultural characteristics, however, plants of the new cultivar ‘COUSORB05’ differ in the following:

-   -   1. Plants of the new variety are more compact.     -   2. Plants of the new variety have yellow-green and pink new         foliage coloration not seen in this comparator.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying photographs illustrate in full color typical plants of ‘COUSORB05’ in Moyenmoutier, France. The photographs were taken using conventional techniques and equipment. While the colors in these photographs may display variances of color as compared to the living cultivar, due to LRV (light reflectance value), they are as accurate as possible using conventional photographic techniques. Colors in the photographs may appear to differ slightly from the color values cited in the botanical description, which accurately describe the colors of the new Sorbaria plant. No artificial light, photoperiodic treatments or chemical treatments were given to the plants.

FIG. 1 illustrates in full color a young ‘COUSORB05’ in the month of April.

FIG. 2 illustrates in full color ‘COUSORB05’ foliage in May.

FIG. 3 illustrates in full color ‘COUSORB05’ foliage in June.

FIG. 4 illustrates in full color a mature ‘COUSORB05’ in the month of September.

DETAILED BOTANICAL DESCRIPTION

In the following description, color references are made to The Royal Horticultural Society Colour Chart 2007 except where general terms of ordinary dictionary significance are used. The following observations and measurements describe ‘COUSORB05’ plants grown outdoors in Vosges, France. Measurements were taken from plants of approximately 2 years of age. Measurements and numerical values represent averages of typical plant types at corresponding states of maturity.

-   Botanical classification: Sorbaria sorbifolia ‘COUSORB05’. -   Propagation:     -   -   Time to initiate roots.—About 21 days at approximately 27°             C.         -   Root description (color, woody, fibrous, branching             characteristics).—Roots are fibrous and somewhat branched.             Newly formed roots are delicate and fleshy, 1 to 2 mm in             diameter. Mature roots are woody and more rigid.         -   Propagation method.—Softwood cuttings. -   Plant:     -   -   Height.—150 cm.         -   Plant spread.—About 100 cm.         -   Plant habit.—Upright globular.         -   Growth rate.—Moderate to rapid.         -   Growth habit.—Upright, compact deciduous shrub.         -   Branching characteristics.—Free branching, 4 to 8 main             branches, suckers and lateral produced.         -   Branch length.—Average range 20 to 45 cm.         -   Branch diameter.—0.6 to 1.4 cm.         -   Branch texture.—Glabrous.         -   Branch color.—Near RHS Grey-Brown 199C.         -   Internode length.—2 to 6 cm.         -   Age of plant described.—About 2 years. -   Foliage:     -   -   Leaf.—Arrangement: Alternate occurring compound leaves.             Length: Average range 20 to 25 cm. Width: Average 7 cm.             Leaflets: Shape: Lanceolate. Quantity: 11 to 17. Occurring             in opposite pairs, with or without a single terminal             leaflet. Length: Average range 5 to 7 cm. Width: Average             2.5 cm. Attachment: Sessile. Apex: Acuminate. Base: Rounded.             Margin: Dentate, crenate. Color: Young foliage first             emerging upper side: Near RHS Red 43C, then fading to Red             43D and Red 38D. Young foliage under side: Near RHS Red 43C,             then fading to Red 43D and Red 38D. Spring semi-mature             foliage upper side: Near RHS Red 38B, 38C and 38D. Turning             Yellow-Green 150C. Spring semi-mature foliage under side:             Near RHS Red 38B, 38C and 38D. Turning Yellow-Green 150C.             Summer mature foliage upper side: Near RHS Green 136B.             Summer mature foliage under side: Near RHS Green 136B.             Venation: Type: Pinnate. Venation color: Upper Surface:             Immature near Red 45D, mature near Yellow-Green 150B. Lower             Surface: Immature near Red 45D, mature near Yellow-Green             150B.         -   Petiole.—         -   Length.—About 2 to 5 cm.         -   Diameter.—About 5 mm.         -   Color.—Immature near Red 45D, mature near Yellow-Green 150B.         -   Texture.—Glabrous. -   Flower: Flowering not observed to date. -   Reproductive organs: Not observed to date. -   Other characteristics:     -   -   Seeds and fruits.—Not observed to date.         -   Disease resistance.—Neither resistance nor susceptibility to             normal diseases and pests of Sorbaria observed to date.         -   Temperature tolerance.—USDA Zones 2 through 11.         -   Drought tolerance.—None observed. 

What is claimed is:
 1. A new and distinct cultivar of Sorbaria plant named ‘COUSORB05’ as herein illustrated and described. 